Stacking systems exist for stacking structural components for the metal industry. For example, stacking systems exist that are capable of stacking structural components produced by purlin roll formers. Purlin roll formers cut and form sheet metal strips into purlins of various lengths. Manufactures of these purlin roll forming machines continue to make these purlin roll forming machines more automatic, to operate at higher speeds and to have faster set up times for different parts.
Typical purlin roll forming line forms component parts of a variety of sizes and cross-sectional shapes, and some such parts require orientation in order to nest and stack adjacent parts. Because of the variables involved in stacking and bundling the parts for shipment, such part orientation and stacking has heretofore been largely a manual operation. In practice, purlin roll formers turn out part lengths of between about 2 to 70 feet. A 40-foot part of maximum thickness (typically 10 gage) and size can weigh up to about 400 pounds or more, and such parts can be produced at a rate of 5 per minute, and a smaller part length part, such as a 10 foot purlin, can be produced at 20 per minute with each weighing up to 100 pounds.
Most purlin roll forming lines require 2 to 3 people stacking the parts. In many instances the line will incur frequent shut downs to wait for the stacking area to clear. The extremely heavy parts may be made of steel and may have sharp edges and points, and are hazardous to persons handling these parts. Thus, labor costs, turnover rates and liability for personal injuries can all be high.
Some machinery manufacturers have designed rudimentary stackers for one type of part but are unable to stack the full range of sizes and shapes. Such stackers, being slow, noisy and damaging to painted part surfaces, require extensive operator intervention.
Thus, there remains a need for improved stacking systems for handling and stacking purlin components, and ideally, such stacking systems would be 1) fully automatic, having operator inputs of load sizes and quantities, and capable of 2) stacking all part sizes manufactured on purlin roll formers and of handling parts coming out of a roll former with part orientation of either flanges up or flanges down.
The system would 3) handle part lengths from 2 to 70 feet, and be capable of 4) stacking cee, zee, U, angle, sigma, etc. purlin cross-sections. It would have a 5) compact design of minimum floor space, extending less than the length of the processing line on the operator side of the line; and it would 6) handle bundle sizes up to about 10,000 pounds or more. Preferably, 7) stack bundles would be tight and square for banding, and the system would 8) avoid damaging painted part surfaces. Finally, the system would be 9) economical to purchase and operate, and it would 10) operate quietly, that is, within an acceptable range of noise generation for its factory surrounding.